Mark McGowan, aka the Artist Taxi Driver, has an audience of over 40,000 for his YouTube political videos, recorded in his minicab. Photograph: Martin Godwin for the Guardian

Mark McGowan spends an awful lot of time in cars, as a minicab driver. To fill the dead time, he records videos on his iPhone – short rants about politics, social and current affairs, and uploads them to YouTube, where he is better known as ChunkyMark, the Artist Taxi Driver. The first videos appeared in 2010, and were watched by only a few hundred people. McGowan’s unscripted and usually expletive-laden clips have now garnered him a formidable audience, with over 42,000 subscribers on the channel, and 40,000 Twitter followers. The 3,057 videos, which have now branched out to include interviews with any political or public figures willing to fill his passenger seat, together with three feature-length films made by Chunky Productions have been viewed more than 11.5m times.

The Artist Taxi Driver persona sprang from a short conversation outside the Frieze art fair in London. “I went to Frieze, and couldn’t get in, and someone said: ‘Are you a taxi driver?’ I said, ‘no, I’m the artist taxi driver’ and that’s how it was born,” he explains.

McGowan, 50, grew up in a working-class family on a council estate in south London in the 1970s. “I was brought up on a really beautiful estate, the North Peckham estate. I loved it,” McGowan says. “Anyone that talks [dismissively] about estates – for a kid it was amazing, absolutely amazing. It’s not like today, you couldn’t wait to go home, leave school, to run around with kids from your estate.”

After a period of what he describes as “skullduggery” he became a mature art student, studying at Camberwell School of Art, and he started a master’s degree at Goldsmiths University, though he didn’t complete it. He has taught art practice and theory at various art colleges and when we meet he is preparing to give a lecture on Scottish politics and the failings of Westminster at the Edinburgh College of Art. He has been driving minicabs for a living for four years, but for a decade, before beginning the Artist Taxi Driver videos, McGowan was best known for his artistic stunts. These include pushing a peanut along the floor with his nose, from Goldsmiths to Downing Street in a protest at student debt; eating what he claims was a swan, followed by a corgi, and attempting to cartwheel from Brighton to London.

These stunts were all politically motivated, he says: cartwheeling from the seaside to highlight the damage caused to British shores by people taking stones home, and dining on swan and corgi “to protest at the Queen” and the royal treatment of animals respectively.

In person, he seems initially shy and speaks in a soft monotone. As we settle into his Nissan Primera he places his new iPhone 5 on the dashboard and begins filming the interview. It is unclear for the next 40 minutes who feels more self-conscious. Once he starts filming, his manner slowly changes, he gets louder, there is more gesticulation, he becomes more of a geezer. It is difficult not to take some of the things he says with a pinch of salt as he moves into performance mode.

“There’s been a massive transformation from being an artist and doing these monologues, to being more like a journalist,” he says of his videos.

McGowan reserves disdain for all three main parties, for supporting privatisation and cuts, and for fostering political disillusionment. “If Labour comes in, they might as well just form a coalition [with the Conservatives],” he says. “All the things that have happened, PFI [private finance initiative for building new hospitals], workfare [employment schemes], privatisation of public services, student fees; the Labour party is as much to blame as the Liberal Democrats, the Tory party – they all work for the same people, for corporations, for banks, looking out for their interests, not people’s interests.”

He is in remission for bowel cancer and married to a nurse, and is passionate about the NHS, but furious at PFI and what he sees as creeping privatisation. “We’re in a mess, we’re in a state. Last weekend they had tents outside hospitals. Politicians seem to be saying: it’s your fault, we’re eating too much, we’re drunk. We’ve got Ukip saying it’s immigrants [causing the strain], and you have all this blame, but where is all the money going?”, he asks.

“Private companies want to make profit from a hospital, so they walk into a place where you’re sick, your children are sick, your life is at risk. Who’s going to pick up the pieces with Circle?”

What angers McGowan most about politics? “The main thing is the ideology of austerity. Under the cloak of austerity, the primary purpose of this government has been to move public money into private pockets,” he says. “You see it every time David Cameron or George Osborne come on telly. They talk about how many jobs they’ve created in the private sector.”

From his back-of-the-cab interviews with campaigners and protesters against the government, he says it is clear who has been hit hardest by the coalition’s cuts. “The people who’ve been hurt the most, which is the people at the bottom, by the attacks, by the cuts to the Independent Living Fund. That’s 18,000 severely disabled people who want to live in the community,” he says. “I’ve interviewed these people and they’ve said: ‘What are we going to do, are we going to live in [residential] homes?’ It’s an ideological move, because it’s so small. Like the bedroom tax, it’s completely ideological.”

Watching McGowan’s videos, it is obvious he appeals to the same audience caught up in Russell Brand’s recent politicking. Does he see himself in the same, anti-politics mould? “Russell has millions of followers and speaks in a way no one with such a large profile has ever done before,” he replies. “I don’t believe he is anti-politics – the exact opposite. He’s calling for a ‘new politics’.”

Contrary to the wishes of a Facebook group of 3,500 fans calling for him to be made prime minister, McGowan says he would not want to be an MP and sees his videos as his political contribution to exposing the coalition. “This government has been and still is despicable,” he says. “We have one million unemployed, we have despicable, heinous workfare schemes, forcing people to go to work for massive corporations, under pain of debt.”

So does he have any answers? Perhaps, unsurprisingly, for an artist, McGowan’s solution is creative. “Do you realise how many albums were written on the dole? Don’t send kids off to do slave labour at Tesco, give them a pen. Give them a guitar.”

Not everyone invited into his cab impresses him, however. “I interviewed George Galloway and I asked him about his comments on rape and Julian Assange, because I felt really uncomfortable talking to him. And I asked him about [former Respect party leader] Salma Yaqoob and said “Did you feel bad about her having to resign?”. He said: ‘In a few years, no one will remember who she was.’” The interview, far shorter than his usual 30 minutes, ends with Galloway being cut off mid-sentence.

He has set his heights high for potential future passengers: Lord Ashcroft has followed him on Twitter and he has sent a message asking him to go on. He says he would also love to interview Bonnie Greer, whose approach to politics he says he greatly admires.

Asked about the 2015 general election, McGowan is more exasperated than hopeful. “I don’t know what’s wrong with society, the government, with hedge fund managers, private equity, and vulture capitalists. When is enough, enough? We need to be creating a society that is better, not a society of growth that says: ‘How much more money can the rich make?’”